1. Field of the Invention
This invention relates to a housing of a portable radio communication device, such as a portable telephone.
2. Description of the Related Art
FIGS. 1 and 2 are perspective views showing conventional portable telephone housings, wherein a cover 1b or 1c has a loudspeaker hole 2, a microphone hole 3, a display window 4, and key buttons 5. A case 6b or 6c and the cover 1b or 1c make up the radio communication device housing. A battery pack 7b or 7c is fixed to the cover 1b or 1c. The cover 1 is equipped with a connector hole 8b and a receptacle 9b of an external power connector, which will hereinafter be referred to as an I/O connector. A plug 10 of the I/O connector, which is provided with a lock release button 11, is attached to one end of a cable 12.
A cigar lighter plug 13 shown in FIG. 3, which is attached to the other end of the cable 12, is a plug that can be fitted into a cigar lighter mounted on a car. A hands-free (H/F) adapter 14 shown in FIG. 4, which is attached to the other end of the cable 12, is an adapter for holding the portable radio communication device and containing a hand-free circuit.
Next, the operation will be described. First, as shown in FIGS. 1, 3, and 4, the portable telephone normally comprises the battery pack 7b for receiving a power supply from the battery cells. However, the battery cell capacity is finite, and for example, when the user uses the portable telephone in a car, he or she may want to receive a power supply from a car battery. To meet this requirement, the portable telephone needs to be equipped with the I/O connector receptacle 9b as shown in FIG. 1.
The cigar lighter adapter 13 is fitted into the cigar lighter section of the car and the I/O connector plug 10 is coupled with the I/O connector receptacle 9b, thereby receiving a power supply from the car battery. Since the I/O connector has a lock structure and the cable 12 is curled, the user can use the portable telephone like a normal home telephone or mobile phone, at a comparatively desirable use position. It is dangerous, when talking with the associated party, for the driver to hold the portable telephone while driving. Thus, the H/F adapter 14 shown in FIG. 4 is provided to enable the user to talk without holding a handset. With the H/F adapter 14, the user can talk with the portable telephone held on the H/F adapter 14.
Thus, the necessity of mounting the I/O connector receptacle 9b as well as the battery pack 7b is extremely high for the portable telephone. Further, user friendliness can be improved by adopting a structure for eliminating the need for unloading the battery pack 7b when the plug 10 of the I/O connector is fitted into the I/O connector receptacle 9b. Therefore, the I/O connector receptacle 9b is located on the bottom of the portable telephone and the battery pack 7b is disposed on the rear.
On the other hand, FIG. 2 shows an example of a portable telephone for which no I/O connector is provided. The battery pack 7 is disposed on the bottom of the portable telephone to make it slim.
Such a structure provides a slim portable telephone, but contains no I/O connector, thus power is only supplied from the battery pack 7. Therefore, a power supply from a car or the like as described above cannot be received.
Since the conventional portable radio communication device housings are formed as described above the thickness of the housing should be more than the total of the thickness of the key switch section and that of the housing, and, if the I/O connector receptacle 9b is disposed on the bottom of the portable telephone housing, the thickness of the battery pack. Therefore it is very difficult to make radio communication device slim. If the battery pack is located on the bottom of the radio communication device housing, no external unit connection connector (I/O connector) can be installed. Therefore, a power supply from the car or the like cannot be received although the housing can be made slim. On the other hand, if an I/O connector is installed, the I/O connector is not usually disposed on the battery pack. Therefore, if the battery pack is not removed, the connector cannot be used. When the battery pack is removed, the removed battery pack is inconvenient to handle.